The Puerto Rican rap duo Calle 13 is one of the most outspoken major music acts to emerge from Latin America since the legendary Ruben Blades. Last week, the band made headlines across the Spanish-speaking world when it released "Multi_Viral," an unlikely collaboration with Julian Assange from WikiLeaks.

The song is largely about media manipulation of information, with Calle 13's members shouting out to recent-vintage protest movements such as Occupy Wall Street and Mexico's #YoSoy132. Midway through "Multi_Viral," Assange is featured speaking about misinformation and the power of popular movements.

In a phone interview with frontman Rene Perez Joglar, he says the goal of the song is to discuss how "media is controlling everything, even people's minds, everything. Here in the U.S., it's worse; it's like a bubble. ... It's important to have the right information, and you are not going to get that from one newspaper or one TV show; you have to look for that. In order to get the full picture, you have to read a lot and look for yourself. Otherwise, you'll find yourself in a war that you think is a good idea, but it's not for a good reason."

The duo has been outspoken since its beginnings in 2005; in the vitriolic "Querido FBI," for example, Joglar goes on a rant about that year's killing of Puerto Rican independence activist Filiberto Ojeda Rios by the FBI. Ever since, Calle 13 has infused its music with a strong social and political conscience.

One of my favorite lines in that song — "Hay fuegos que con agua no se apagan" — translates as, "There are fires that cannot be extinguished with water." For its part, Calle 13 has been on fire for a long time.

Tune in to this week's episode of Alt.Latino for some great music and conversation, and let us know: What songs are lighting your fire these days?